diff options
Diffstat (limited to 'kernel/power')
-rw-r--r-- | kernel/power/hibernate.c | 20 | ||||
-rw-r--r-- | kernel/power/main.c | 55 | ||||
-rw-r--r-- | kernel/power/suspend.c | 4 |
3 files changed, 72 insertions, 7 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index aa9e916da4d..f6120291663 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -277,7 +277,7 @@ static int create_image(int platform_mode) goto Enable_irqs; } - if (hibernation_test(TEST_CORE)) + if (hibernation_test(TEST_CORE) || !pm_check_wakeup_events()) goto Power_up; in_suspend = 1; @@ -288,8 +288,10 @@ static int create_image(int platform_mode) error); /* Restore control flow magically appears here */ restore_processor_state(); - if (!in_suspend) + if (!in_suspend) { + events_check_enabled = false; platform_leave(platform_mode); + } Power_up: sysdev_resume(); @@ -511,14 +513,20 @@ int hibernation_platform_enter(void) local_irq_disable(); sysdev_suspend(PMSG_HIBERNATE); + if (!pm_check_wakeup_events()) { + error = -EAGAIN; + goto Power_up; + } + hibernation_ops->enter(); /* We should never get here */ while (1); - /* - * We don't need to reenable the nonboot CPUs or resume consoles, since - * the system is going to be halted anyway. - */ + Power_up: + sysdev_resume(); + local_irq_enable(); + enable_nonboot_cpus(); + Platform_finish: hibernation_ops->finish(); diff --git a/kernel/power/main.c b/kernel/power/main.c index b58800b21fc..62b0bc6e498 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -204,6 +204,60 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, power_attr(state); +#ifdef CONFIG_PM_SLEEP +/* + * The 'wakeup_count' attribute, along with the functions defined in + * drivers/base/power/wakeup.c, provides a means by which wakeup events can be + * handled in a non-racy way. + * + * If a wakeup event occurs when the system is in a sleep state, it simply is + * woken up. In turn, if an event that would wake the system up from a sleep + * state occurs when it is undergoing a transition to that sleep state, the + * transition should be aborted. Moreover, if such an event occurs when the + * system is in the working state, an attempt to start a transition to the + * given sleep state should fail during certain period after the detection of + * the event. Using the 'state' attribute alone is not sufficient to satisfy + * these requirements, because a wakeup event may occur exactly when 'state' + * is being written to and may be delivered to user space right before it is + * frozen, so the event will remain only partially processed until the system is + * woken up by another event. In particular, it won't cause the transition to + * a sleep state to be aborted. + * + * This difficulty may be overcome if user space uses 'wakeup_count' before + * writing to 'state'. It first should read from 'wakeup_count' and store + * the read value. Then, after carrying out its own preparations for the system + * transition to a sleep state, it should write the stored value to + * 'wakeup_count'. If that fails, at least one wakeup event has occured since + * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it + * is allowed to write to 'state', but the transition will be aborted if there + * are any wakeup events detected after 'wakeup_count' was written to. + */ + +static ssize_t wakeup_count_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + unsigned long val; + + return pm_get_wakeup_count(&val) ? sprintf(buf, "%lu\n", val) : -EINTR; +} + +static ssize_t wakeup_count_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (sscanf(buf, "%lu", &val) == 1) { + if (pm_save_wakeup_count(val)) + return n; + } + return -EINVAL; +} + +power_attr(wakeup_count); +#endif /* CONFIG_PM_SLEEP */ + #ifdef CONFIG_PM_TRACE int pm_trace_enabled; @@ -236,6 +290,7 @@ static struct attribute * g[] = { #endif #ifdef CONFIG_PM_SLEEP &pm_async_attr.attr, + &wakeup_count_attr.attr, #ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, #endif diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index f37cb7dd440..5f8d09f9432 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -163,8 +163,10 @@ static int suspend_enter(suspend_state_t state) error = sysdev_suspend(PMSG_SUSPEND); if (!error) { - if (!suspend_test(TEST_CORE)) + if (!suspend_test(TEST_CORE) && pm_check_wakeup_events()) { error = suspend_ops->enter(state); + events_check_enabled = false; + } sysdev_resume(); } |